Detective Jeremiah MacKay, 35 of Redlands, was pronounced dead yesterday afternoon.
"My sincerest condolences go out to the MacKay family," McMahon said. "This is truly another sad day for law enforcement. Our department is grieving from this event. It's just a terrible ordeal for all of us."
MacKay was with the department for 15 years and was stationed in Yucaipa, but had previously been stationed in Big Bear, McMahon said.
He is survived by his wife, 7-year-old daughter and four-month-old son.
A second deputy was severely injured in the shootout and has been identified as Alex Collins. He is being treated at Loma Linda University Medical Center.
"We just spoke to his wife. He is in good spirits and should make a full recovery after a number of additional surgeries," McMahon said.
McMahon also confirmed the conclusion of the manhunt for Dorner, although the remains found in a burned out cabin have yet to be identified.